This section is intended to introduce the reader to various aspects of art, which may be related to various aspects of the present invention that are described and/or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present invention. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.
A macrocell is a cell in a mobile phone network that provides radio coverage served by a cellular base station, namely a NodeB in a universal mobile telecommunication system (UMTS) network. It is adapted to connect cellular handsets to a mobile network. The area covered by a base station is called a cell. When a cellular handset is located in a cell, it can connect to the base station. A location area is a set of base stations that are grouped to optimize signaling. Each location area comprises one or more network cells.
A femtocell, also called an access point base station or a Home Node B, is a cellular base station. From a mobile handset, it is functionally similar to a macrocell cellular base station. A femtocell is adapted to cover a much lower cell range than a macrocell. The cell size covered by a femtocell is called a pico cell hereinafter. The pico cell may also be called a femtocell hereinafter. A typical use of a femtocell is inside a building to cover areas that are not reached by a macrocell. A cellular service operator provides a plurality of macrocells and femtocells. The femtocell is usually connected to the service provider network through a broadband connection. The broadband connection is used as the backhaul link to the mobile operator's network. Therefore, the availability of this broadband connection determines alternative use of the 3G radio connection between the femtocell and a User Equipment (UE). One such alternative is to control the home network environment. In femtocell operation, under the normal circumstance, the 3G radio of the femtocell is likely to be turned off when the broadband connection goes down. One obvious reason is that, when the broadband connection is down, no call can be made using the femtocell as the backhaul link is not available. However, loss of 3G radio link between the femtocell and the UE implies that UE can not be used to control the home network environment.